International Journal of Advancements in Research & Technology, Volume 3, Issue 12, December -2014
ISSN 2278-7763
72
INFLUENCE OF SUPERPLASTISIZER ON FLOW
AND STRENGTH CHARACTERISTICS OF
CONCRETE
Sishminder Pal Singh
In Guidance of
I K Chaitanya
Civil Engineering Department,
Raghu Engineering College,
Visakhapatnam,
India.
Email: sishminder@gmail.com
ABSTRACT
As civil engineer’s maintaining our duty to discover method of making concrete at lowest water cement ratio while maintain a
required workability. It is now possible with the advent of super plasticizers. Today new applications of admixture have been
brought into the market for production of high strength and flowing concretes. These super plasticizers were also suitable for use
with other cement material like FLY ASH and PPC. The effects of super plasticizer on fresh and hardened concrete were
investigated. The experiment program included test on workability, slump loss and compressive strength. In this experimental
works we are comparing the properties of super plasticizer based concrete with that of without super plasticizer added concrete.
Super plasticizer permitted a significant water reduction while maintain the same workability.
In these research program three different families of super plasticizers has been used.
Rheobuild 1125(Sulphonated naphthalene polymer based)
Glenium 140 (Polycarboxylic ether polymers)
Pozzolith 225 (Modified lignosulphate)
Two design ratios of M20 and M40 grade were used for mix proportioning of concrete constitute by weight. The water cement
ratio were maintained as 0.55, 0.40, to study the effect of these super plasticizer on various properties of concrete. The dosages of
super plasticizer were adopted as 0.25% by weight of cement. To study the effect of super plasticizer the experiment has been
divided into four series namely workability series, water reduction series and cement saving series, compressive strength.
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Keywords—Super Plasticizers, Fly Ash, Rheobuild, Glenium, Pozzolith
INTRODUCTION
The earliest known published reference to the use of small
amounts of organic material to increase the fluidity of cement
containing composition was made in 1932 where polymerized
naphthalene formaldehyde sulphonate salts were claimed as
useful in this role. This was followed during the mids 1930s to
early 1940s by numerous disclosures regarding the use of
lignosulphonate and improved composition In recent years,
construction agencies in North America, Great Britain and
other countries have evinced great interest in the use of super
plasticizers, super fluidifiers, sipper water reducers or high
range water reducers. The super plasticizers’ (SP) are referred
to as high range water reducing admixture by ASTMC494,
which mainly disperses the water in concrete matrix. This
property is some time called as Dispersion-fluidification
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property of concrete admixture. According to the United
Nations, there will be at least 20 megacities of more than 10
million habitants in the year 2025. These cities will require
large amounts of construction material for buildings and
municipal infrastructures as well as for facilities necessary to
handle food, drinking water and sewage. With an annual
production of approximately 7 billion tons, Portland cement
concrete is the most commonly used construction material
throughout the world and it is expected that its use will
continue to expand significantly in the next few years. Mostly
due to its relative low cost, easy availability and versatility,
Portland cement concrete has found many useful applications,
from massive dams to high-rise buildings.
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International Journal of Advancements in Research & Technology, Volume 3, Issue 12, December -2014
ISSN 2278-7763
The super plasticizers are classified in the following four
major groups;
Sulphonated Naphthalene Formaldehyde polymer based
(SNF).
Polycarboxylic ether polymers.(PCEP)
Modified Lignosulphonate (MLS).
Others
Chemistry of super plasticizer
In terms of chemical structure, superplasticizers can be
broadly classified into two general categories. The first
categories, the sulfonates-based superplasticizers, are the most
important group of superplasticizers currently in use in the
concrete industry. The first and most widely accepted
compounds of this group are the poly-b-naphthalene
sulfonates (PNS), the molecular structure of which is
illustrated in. The synthesis of PNS superplasticizers involves
several steps. It begins with the sulfonation of molten
naphthalene with concentrated sulfuric acid at high
temperature and pressure for several hours, followed by
condensation of the b-naphthalene sulfonates with
formaldehyde, neutralization with a suitable alkali and
filtration to eliminate calcium sulfate. The resulting product is
clear dark-colored liquid containing between 30 and 40%
solids. Poly melamine sulfonates (PMS) are a second family
of sulfonates superplasticizers that are also widely used in the
concrete industry. First, formaldehyde reacts with the amino
groups of melamine in alkaline conditions, yielding an
addition product containing one or more methylol groups
(CH2OH), depending on the formaldehyde/melamine ratio.
Sulfonation of one of the methylol groups is then performed
using sodium bisulfite under the same alkaline conditions.
Polymerization of the sulfonates monomeric units is then
initiated by mild heating under slightly acidic conditions.
Finally, when the desired degree of polymerization has been
obtained, the reaction is stopped by increasing the pH to
slightly basic pH values and the final product is filtered to
eliminate any non-desirable byproducts. Organic polymers
bearing carboxylic acid groups constitute the second category
of superplasticizers. Several polycarboxylate polymers and in
particular poly acrylates have been proposed as concrete
superplasticizers since the early 1980’s.
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in a weakening of the mechanical properties of concrete and in
a decrease of its durability. Superplasticizers are powerful
dispersing agents. As with most dispersing agents in aqueous
solutions, they first act by being adsorbed onto the surface of
cement particles. As illustrated in a significant proportion of
the added superplasticizer is adsorbed onto cement particles at
concentration commonly used in concrete. A schematic
description of the adsorption mechanism is shown.Adsorption
of negatively charged PNS on the surface of cement particles
that are also negatively charged is made possible by the
presence of calcium ions that have been solubilized from the
cement.
Following adsorption of the superplasticizer, several physicchemical effects might take place in the cement paste. For
instance, the adsorbed superplasticizer molecules might
contribute to minimize interactions particles through
electrostatic repulsive forces or to the induction of short-range
repulsive forces due to steric hindrance between polymer
layers.
Superplasticizer molecules might also adsorb preferentially
onto the aluminate phases of cements (particularly C3A) and
compete with SO4² ions in the reactions that control the early
hydration of C3A.
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Mode of Action of Super plasticizers
It has long been known that the strength of any given concrete
is inversely related to the water/cement ratio, i.e. the lower the
water content of the concrete, the stronger it is. Water is an
essential ingredient of concrete where it plays two basic roles:
1) It gives concrete the required rheological properties and
2) It participates in the reactions of hydration. The ideal
concrete should thus only contain the minimal quantity of
water necessary to develop the maximum possible strength of
cement while providing sufficient workability for placement.
However, since cement particles have a strong tendency to
flocculate when they are brought in contact with water, it is
necessary to add more water than is necessary in order to
obtain a certain level of workability. Since this additional
water will never be used in the hydration reactions, it will
generate porosity within the hydrated cement paste, resulting
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EXPERIMENTAL DETAILS
Material used:
Cement: Portland pozzolona cement was used.
Fine Aggregates: Fine aggregate consisting of natural sand
from rivers
Coarse Aggregates: Locally available coarse aggregate
obtained from quarry, consisting of naturally crushed rock of
nominal maximum size 0f 20mm .......
Series No 1
Design of grade M20 and M40 mixes prepared in the lab as
per IS 10262:2009. Four mixes with each type of super
plasticizers have been developed for the 12 mixes.
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International Journal of Advancements in Research & Technology, Volume 3, Issue 12, December -2014
ISSN 2278-7763
74
Series No 2
To investigate the effect of Super plasticizers on workability
slump tests were carried out and to check the slump loss
within time is observed.
Series No 3
To investigates effect on compressive strength cubes [6*6*6]
were tested at the ages of 7, 14, 28 days. The results are shown
in Table
RESULT AND ANALYSIS
•
Table I Test result of the graph showing compressive
strength at constant w/c ratio of M20 grade concrete
From this graph the following points to be pointed out:
Glenium140 has got the7 days strength more than any other
type of superplasticizers and conventional concrete.
Conventional concrete give the higher strength than any other
concrete using superplasticizer at 14 days.
Conventional concrete give the target mean strength at 28 days
and also highest strength comparing three different types of
superplasticizers.
•
Table III Combination of graph showing the result of
slump loss at every 10 min for grade M20 by using three
different families of superplasticizer and a conventional
concrete:
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From this graph the following points to be pointed out:
Conventional concrete has got the7 days strength more than
any other type of superplasticizers and conventional concrete.
Conventional concrete give the higher strength than any other
concrete using superplasticizer at 14 days.
Conventional concrete give the target mean strength at 28 days
and also highest strength comparing three different types of
superplasticizers.
Table II Test result of the graph showing compressive strength
at constant w/c ratio of M40 grade concrete
This is the graph showing combination of three super
plasticizer and conventional concrete showing there slump
loss at every 10 min, from this graph it is shown that
Rehobuild1125 show maximum slump at 0min but is not
workable , after 20 min its workability fall to zero. But the
conventional concrete is workable for 30 min.
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International Journal of Advancements in Research & Technology, Volume 3, Issue 12, December -2014
ISSN 2278-7763
Table IV Combination of graph showing the result of slump
loss at each 10 min for grade M40 by using three different
families of superplasticizer and a conventional concrete
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F. Table VI Test result showing effect of superplasticizer on
water reduction and compression strength at constant
workability for grade M40
Superplas Wate Wate Slump Compressive
ticizer
rr
(mm) strength (N/mm²)
used
cem reduc
ent
tion
ratio
7
14
28
days days days
This is the graph showing combination of three
superplasticizer and conventional concrete showing there
slump loss at every 10 min, from this graph it is shown that
rehobuild1125 show maximum slump at 0min but is not
workable , after 20 min its workability fall to zero. But the
conventional concrete is workable for 30 min
Rheobuil
d 1125
0.40
29%
10
20.4
3
28.8
8
35.5
7
Glenium
140
0.40
29%
0
25.3
3
30.4
4
36.6
7
Pozzolith
225
0.40
29%
0
17.7
7
26.6
7
35.5
6
Glenium 140 has got the highest strength in 7 days
compressive strength than any other superplasticizer concrete.
In 14 days compressive strength is higher for Glenium 140. In
28 days the result is totally different, Glenium 140 has got the
strength higher than any other superplasticizer concrete.
Applications:
Today super plasticizers are used in all important projects
across the world in high raise buildings, pre stressed concrete,
slender components with congested and densely packed
reinforcement, beams and slabs pre-cast elements and long
slender columns.
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Table V Test result showing effect of superplasticizer on water
reduction and compression strength at constant workability for
grade M20
Advantages:
The super plasticizer affect the various properties of concrete
both in fresh and hardened forms like::
Superp Wa
lasticiz tercem
er used ent
rati o
Wa
ter
red
ucti
on
Slu Compressive
mp( strength (N/mm²)
mm
)
7
14
28
days days days
Rheob
uild
1125
0.55
29
%
10
12.0
15.5
22.22
Gleniu
m 140
0.55
29
%
10
14.8
18.2
22.67
Pozzoli 0.55
th 225
29
%
5
13.3
14.6
23.11
Glenium 140 has got the highest strength in 7 days
compressive strength than any other superplasticizer concrete.
14 days compressive strength is higher for Glenium 140.In 28
days the result is totally different, Pozzolith 225 has got the
strength higher than any other superplasticizer concrete.
Copyright © 2014 SciResPub.
•
Reduction in interfacial tension.
•
Multilayered adsorption of Organic molecule.
•
Release of water trapped amongst the cement
particles.
•
Retarding effect of cement hydration.
Change in morphology of hydrated cement
Conclusion:

This paper was conducted to study the effect of
superplasticizer on properties of concrete with
characteristic strength of 20 N/mm². The properties
investigated were workability (Slump), and
compressive strength.
 Glenium 140 have shown however more pronounced
in terms of increase in the compressive strength,
workability, water reduction, cement saving
requirements of concretes.
From the results of the study the workability of concrete can
be increased by addition of superplasticizer
REFERENCES
[1] Saeed Ahmad, Muhammad Nawaz, Ayub Elahi - ―Effect of
super plasticizers on workability and strength of concrete‖ 30th
Conference on our world in concrete & structures: 23 - 24 August
2005.
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International Journal of Advancements in Research & Technology, Volume 3, Issue 12, December -2014
ISSN 2278-7763
[2] Salahaldein Alsadey - ―Effects of super plasticizing Admixture
on Properties of Concrete‖ International Conference on Transport,
Environment and Civil Engineering (ICTECE'2012) August 25-26,
2012.
[3] M. Palacios, F. Puertas - ―Effect of superplasticizer and
shrinkage-reducing admixtures on alkali-activated slag pastes and
mortars‖ Cement and Concrete Research 35 (2005) 1358– 1367.
[4] A. KAPELKO - ―The possibility of adjusting concrete
mixtures’ fluidity by means of superplasticizer SNF‖ Archives of
civil and mechanical 2006.
76
[.
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